{"rsdb":{"rid":"376850","subhead":"","postdate":"0","aid":"263781","fid":"90","uid":"1","topic":"1","content":"<div id=\"cnblogs_post_body\" class=\"blogpost-body cnblogs-markdown\"> \n <h2 id=\"operators\">Operators<\/h2> \n <ul> \n  <li><code>Thread.`yield`()<\/code> \u53cd\u5f15\u53f7\u9664\u4e86\u7528\u4e8e\u547d\u540d\u6807\u8bc6\u7b26\uff0c\u8fd8\u53ef\u4ee5\u5728\u8c03\u7528\u65b9\u6cd5\u65f6\u907f\u514d\u51b2\u7a81(<code>yield<\/code> \u4e3a Scala \u5173\u952e\u5b57\uff0c\u4f46\u4e5f\u662f <code>Thread<\/code> \u7684\u65b9\u6cd5)<\/li> \n  <li>\u4e2d\u7f00\u8fd0\u7b97\u7b26(infix operators)\uff0c\u5b9e\u9645\u662f\u5e26\u4e24\u4e2a\u53c2\u6570\u7684\u65b9\u6cd5\uff0c\u5b9a\u4e49\u65f6\u8ddf\u666e\u901a\u65b9\u6cd5\u4e00\u6837\uff1b<code>a to b<\/code> \u5b9e\u9645\u662f <code>a.to(b)<\/code><\/li> \n  <li>\u4e00\u5143\u8fd0\u7b97\u7b26(unary operators) \n   <ul> \n    <li><code>+, -, !, ~<\/code>\u56db\u4e2a\u53ef\u5f53\u505a\u524d\u7f00\u8fd0\u7b97\u7b26\u4f7f\u7528\uff0c<code>-a<\/code> \u5b9e\u9645\u662f <code>a.unary_<\/code><\/li> \n    <li>\u5982\u679c\u53ef\u653e\u5728\u53c2\u6570\u540e\uff0c\u5219\u662f\u540e\u7f00\u8fd0\u7b97\u7b26 <code>a identifier<\/code><\/li> \n   <\/ul><\/li> \n  <li>\u8d4b\u503c\u64cd\u4f5c\u7b26(assignment operators)\uff0c<code>a operator= b<\/code> \u7b49\u4ef7\u4e8e <code>a = a operator b<\/code><\/li> \n  <li>\u4f18\u5148\u6027 \n   <ul> \n    <li><code>* \/ %<\/code> &gt; <code>+ -<\/code> &gt; <code>:<\/code> &gt; <code>&lt; &gt;<\/code> &gt; <code>! =<\/code> &gt; <code>&amp;<\/code> &gt; <code>^<\/code> &gt; <code>|<\/code> &gt; \u975e\u64cd\u4f5c\u7b26 &gt; \u8d4b\u503c\u64cd\u4f5c\u7b26<\/li> \n    <li>\u4e2d\u7f00\u8fd0\u7b97\u7b26\u4f18\u5148\u4e8e\u540e\u7f00\u8fd0\u7b97\u7b26<\/li> \n   <\/ul><\/li> \n  <li>\u7ed3\u5408\u6027 \n   <ul> \n    <li>\u6240\u6709\u64cd\u4f5c\u7b26\u90fd\u662f\u5de6\u7ed3\u5408\u7684\uff0c<strong>\u9664\u4e86\uff1a<\/strong> \n     <ul> \n      <li>\u4ee5 <code>:<\/code> \u7ed3\u5c3e\u7684\u64cd\u4f5c\u7b26 \n       <ul> \n        <li><code>1 :: 2 :: Nil<\/code> \u5b9e\u9645\u662f <code>1 :: (2 :: Nil)<\/code><\/li> \n        <li>\u53f3\u7ed3\u5408\u7684\u4e8c\u5143\u64cd\u4f5c\u7b26\u5b9e\u9645\u662f\u7b2c\u4e8c\u4e2a\u64cd\u4f5c\u5bf9\u8c61\u7684\u65b9\u6cd5\uff0c\u5982 <code>2 :: Nil<\/code> \u662f <code>Nil.::(2)<\/code><\/li> \n       <\/ul><\/li> \n      <li>\u8d4b\u503c\u64cd\u4f5c\u7b26<\/li> \n     <\/ul><\/li> \n   <\/ul><\/li> \n  <li>\u5982\u679c <code>f(a,b,c)<\/code> \u8c03\u7528\u65f6 <code>f<\/code> \u4e0d\u662f\u51fd\u6570\u6216\u65b9\u6cd5\uff0c\u5219\u7b49\u4ef7\u4e8e <code>f.apply(a,b,c)<\/code> \n   <ul> \n    <li><code>f(a,b,c) = value<\/code> \u5219\u7b49\u4ef7\u4e8e <code>f.update(a,b,c, value)<\/code>\uff1b\u5982\u9488\u5bf9 <code>HashMap<\/code> \u7684\u53d6\u503c\u548c\u8d4b\u503c<\/li> \n    <li>\u5e38\u7528\u6765\u6784\u5efa\u5bf9\u8c61\u65f6\uff0c\u7701\u7565 <code>new<\/code> \u5173\u952e\u5b57<\/li> \n   <\/ul><\/li> \n  <li>\u63d0\u53d6\u5668 extractors \n   <ul> \n    <li>\u5305\u542b <code>unapply<\/code> \u65b9\u6cd5\u7684\u4f34\u751f\u5bf9\u8c61\uff0c\u4f34\u751f\u5bf9\u8c61\u53ef\u4ee5\u5b9a\u4e49\u6210\u7ed9\u4efb\u610f\u7c7b\u578b\u505a\u4e3a\u63d0\u53d6\u5668(\u5982\uff0c\u4e3a String \u81ea\u5b9a\u4e49\u4e00\u4e2a\u63d0\u53d6\u5668 Name)<\/li> \n    <li>\u5728\u53d8\u91cf\u5b9a\u4e49\u65f6\u4f7f\u7528<\/li> \n    <li>\u5728\u6a21\u5f0f\u5339\u914d\u4e2d\u4f7f\u7528 \n     <ul> \n      <li><code>case class<\/code> \u81ea\u52a8\u9644\u5e26 <code>apply<\/code> \u548c <code>unapply<\/code> \u65b9\u6cd5\uff0c\u5728\u6a21\u5f0f\u5339\u914d\u4e2d\u4f1a\u81ea\u52a8\u8c03\u7528<\/li> \n     <\/ul><\/li> \n    <li>\u63d0\u53d6\u4efb\u610f\u5e8f\u5217\u503c\uff0c\u9700\u8981\u5305\u542b <code>unapplySeq<\/code> \u65b9\u6cd5\uff0c\u8fd4\u56de <code>Option[Seq[Type]]<\/code> \n     <ul> \n      <li>~<del><strong>\u6ce8\u610f<\/strong>\uff0c<code>unapply<\/code> \u548c <code>unapplySeq<\/code> \u7684\u53c2\u6570\u7c7b\u578b\u4e0d\u8981\u5b9a\u4e49\u6210\u4e00\u6837\u7684<\/del>~<\/li> \n     <\/ul><\/li> \n   <\/ul><\/li> \n  <li>\u52a8\u6001\u8c03\u7528 dynamic invocation \n   <ul> \n    <li>\u5b9a\u4e49\u52a8\u6001\u7c7b\u578b \n     <ul> \n      <li><code>import scala.language.dynamics<\/code><\/li> \n      <li>\u7ee7\u627f <code>scala.Dynamic<\/code><\/li> \n     <\/ul><\/li> \n    <li>Scala \u5904\u7406\u8fc7\u7a0b \n     <ul> \n      <li><code>foo.method(&quot;blah&quot;)<\/code> ~&gt; <code>foo.applyDynamic(&quot;method&quot;)(&quot;blah&quot;)<\/code><\/li> \n      <li><code>foo.method(x = 1, 2)<\/code> ~&gt; <code>foo.applyDynamicNamed(&quot;method&quot;)((&quot;x&quot;, 1), (&quot;&quot;, 2))<\/code><\/li> \n      <li><code>foo.field<\/code> ~&gt; <code>foo.selectDynamic(&quot;field&quot;)<\/code><\/li> \n      <li><code>foo.varia = 10<\/code> ~&gt; <code>foo.updateDynamic(&quot;varia&quot;)(10)<\/code><\/li> \n      <li><code>foo.arr(10) = 13<\/code> ~&gt; <code>foo.selectDynamic(&quot;arr&quot;).update(10, 13)<\/code><\/li> \n      <li><code>foo.arr(10)<\/code> ~&gt; <code>foo.applyDynamic(&quot;arr&quot;)(10)<\/code><\/li> \n     <\/ul><\/li> \n   <\/ul><\/li> \n <\/ul> \n <h2 id=\"files-regexp\">Files &amp; RegExp<\/h2> \n <ul> \n  <li>\u8bfb\u53d6\u6240\u6709\u884c <code>Source.fromFile({name\/<a href=https:\/\/www.cppentry.com style=text-decoration:underline;font-size:14px;color:#F70968; target=_blank>java<\/a>.io.File}).getLines.toArray<\/code>\uff0c\u5173\u95ed\u8d44\u6e90 <code>source.close<\/code><\/li> \n  <li>\u8bfb\u53d6\u5b57\u7b26\uff0c\u76f4\u63a5\u8fed\u4ee3 source<\/li> \n  <li>\u8bfb\u53d6\u6807\u51c6\u8f93\u5165 <code>scala.io.StdIn<\/code><\/li> \n  <li>\u8bfb\u53d6 URL <code>Source.fromURL(url, &quot;UTF-8&quot;)<\/code><\/li> \n  <li>\u8bfb\u53d6\u5b57\u7b26\u4e32 <code>Source.fromString(&quot;Hello ww&quot;)<\/code><\/li> \n  <li>\u8bfb\u53d6\u4e8c\u8fdb\u5236\u6587\u4ef6\uff0c\u4f7f\u7528 Java \u7684\u5e93<\/li> \n  <li>\u5199\u6587\u4ef6\u4f7f\u7528 Java \u7684\u5e93<\/li> \n  <li>\u5e8f\u5217\u5316 <code>@SerialVerionUID(42L) class Name extends Serializable<\/code> \n   <ul> \n    <li><code>Serializable<\/code> \u4e3a Scala \u4e2d\u7684 <code>trait<\/code><\/li> \n    <li>\u4e5f\u53ef\u7701\u7565\u6ce8\u89e3\uff0c\u4f7f\u7528\u9ed8\u8ba4\u7684 UID<\/li> \n    <li>Scala \u7684\u96c6\u5408\u90fd\u662f\u5e8f\u5217\u5316\u7684<\/li> \n   <\/ul><\/li> \n  <li>\u8fdb\u7a0b\u63a7\u5236 \n   <ul> \n    <li>\u5de5\u5177\u5305 <code>scala.sys.process<\/code>\uff0c\u5305\u542b\u9690\u5f0f\u8f6c\u6362\u5c06 <code>String<\/code> \u8f6c\u4e3a <code>ProcessBuilder<\/code><\/li> \n    <li>\u6267\u884c shell \n     <ul> \n      <li><code>&quot;ls -l&quot;.!<\/code>\uff0c <code>!<\/code> \u4f1a\u6267\u884c <code>ProcessBuilder<\/code> \u5e76\u963b\u585e\u76f4\u5230\u547d\u4ee4\u9000\u51fa\u5e76<strong>\u8fd4\u56de\u9000\u51fa\u7801<\/strong><\/li> \n      <li><code>&quot;ls -l&quot;.!!<\/code> \u4f1a\u5c06<strong>\u8f93\u51fa\u4f5c\u4e3a\u5b57\u7b26\u4e32<\/strong>\u8fd4\u56de<\/li> \n      <li><code>#|<\/code> \u7ba1\u9053\uff1a <code>(&quot;ls -l&quot; #| &quot;grep scala&quot;).!<\/code><\/li> \n      <li><code>#&gt;<\/code> \u91cd\u5b9a\u5411\u8f93\u51fa\uff1a <code>(&quot;ls -l&quot; #&gt; new File(&quot;out.txt&quot;)).!<\/code><\/li> \n      <li><code>#&gt;&gt;<\/code> \u8ffd\u52a0\uff1a<code>(&quot;ls -l&quot; #&gt;&gt; new File(&quot;out.txt&quot;)).!<\/code><\/li> \n      <li><code>#&lt;<\/code> \u91cd\u5b9a\u5411\u8f93\u5165\uff1a \n       <ul> \n        <li><code>(&quot;grep scala&quot; #&lt; new File(&quot;out.txt&quot;)).!<\/code><\/li> \n        <li><code>(&quot;grep html&quot; #&lt; new URL(&quot;http:\/\/baidu.com&quot;)).!<\/code><\/li> \n       <\/ul><\/li> \n      <li>\u8bbe\u7f6e\u6267\u884c\u76ee\u5f55\/\u73af\u5883\u53d8\u91cf <code>Process(&quot;ls -l&quot;, new File(&quot;..\/&quot;), (&quot;LANG&quot;, &quot;en_US&quot;)).!<\/code>\uff0c\u73af\u5883\u53d8\u91cf\u4e3a <code>(k, v)<\/code> \u5e8f\u5217<\/li> \n     <\/ul><\/li> \n    <li>\u5728 Java \u9879\u76ee\u4e2d\u6267\u884c Scala \u811a\u672c <code>ScriptEngine engine = new ScriptEngineManager().getScriptEngineByName(&quot;scala&quot;)<\/code><\/li> \n   <\/ul><\/li> \n  <li>\u6b63\u5219\u8868\u8fbe\u5f0f<br \/> * \u5de5\u5177\u7c7b <code>scala.util.matching.Regex<\/code><br \/> * \u6784\u9020\u6b63\u5219\u5bf9\u8c61 <code>val pattern = &quot;[0-9]+&quot;.r<\/code><br \/> * \u5b58\u5728\u8f6c\u4e49\u3001\u5f15\u53f7\u7b49\u60c5\u51b5\u65f6\u4f7f\u7528 <code>&quot;&quot;&quot;<\/code>\uff0c<code>val pattern = &quot;&quot;&quot;\\s+[0-9]+\\s+&quot;&quot;&quot;.r<\/code><br \/> * \u6355\u83b7\u7ec4\u4f7f\u7528\u62ec\u53f7\u8868\u793a <code>val patternName = &quot;([0-9]+) ([a-z]+)&quot;.r<\/code><br \/> * \u53ef\u5b9a\u4e49\u6b63\u5219\u53d8\u91cf\u4f5c\u4e3a\u63d0\u53d6\u5668 <code>val pattern(num, item) = &quot;123 abc&quot;<\/code> (<code>patternName<\/code> \u4e0e\u5b9a\u4e49\u7684\u6b63\u5219\u540d\u4e00\u81f4)<br \/> * \u4e5f\u53ef\u5728 for \u5faa\u73af\u4e2d\u4f7f\u7528\u6b63\u5219\u53d8\u91cf\u76f4\u63a5\u63d0\u53d6\u6355\u83b7\u7ec4<\/li> \n <\/ul> \n<\/div>","orderid":"0","title":"Scala Operators, File & RegExp","smalltitle":"","mid":"0","fname":"Scala","special_id":"0","bak_id":"0","info":"0","hits":"249","pages":"1","comments":"0","posttime":"2019-10-09 20:01:15","list":"1570622475","username":"admin","author":"","copyfrom":"","copyfromurl":"","titlecolor":"","fonttype":"0","titleicon":"0","picurl":"https:\/\/www.cppentry.com\/upload_files\/","ispic":"0","yz":"1","yzer":"","yztime":"0","levels":"0","levelstime":"0","keywords":"<A HREF='https:\/\/www.cppentry.com\/do\/search.php?type=keyword&keyword=Scala' target=_blank>Scala<\/A> <A HREF='https:\/\/www.cppentry.com\/do\/search.php?type=keyword&keyword=Operators' target=_blank>Operators<\/A> <A HREF='https:\/\/www.cppentry.com\/do\/search.php?type=keyword&keyword=File' target=_blank>File<\/A> <A HREF='https:\/\/www.cppentry.com\/do\/search.php?type=keyword&keyword=RegExp' target=_blank>RegExp<\/A>","jumpurl":"","iframeurl":"","style":"","template":"a:3:{s:4:\"head\";s:0:\"\";s:4:\"foot\";s:0:\"\";s:8:\"bencandy\";s:0:\"\";}","target":"0","ip":"14.17.22.32","lastfid":"0","money":"0","buyuser":"","passwd":"","allowdown":"","allowview":"","editer":"","edittime":"0","begintime":"0","endtime":"0","description":"Scala Operators, File & RegExp","lastview":"1714840045","digg_num":"0","digg_time":"0","forbidcomment":"0","ifvote":"0","heart":"","htmlname":"","city_id":"0"},"page":"1"}